JP4215686B2 - Strength element and its deterioration diagnosis method - Google Patents

Description

  The present invention relates to a load-bearing element attached to a structure, and further to an earthquake-resistant element attached to a steel building and a method for diagnosing the deterioration.

  Conventionally, there are almost no restoration indices due to earthquake disasters in houses, that is, no suggestion has been made on how much the restoration should be based on the disaster situation.

  For example, in the “Damage Criteria and Standards for Restoration of Earthquake Damaged Buildings” (Non-Patent Document 1) published by the Japan Building Disaster Prevention Association, the rust-prevention paint peeling status and degree of distortion are shown in photographs. It is suggested that if the amount of strain received by the steel member can be evaluated based on the state of peeling of the rust preventive paint, it will be useful in determining the range to be restored in the restoration design.

  In addition, in the “1995 Hyogoken Nanbu Earthquake Steel Building Damage Survey Report” (Non-Patent Document 2) issued by the Japan Architectural Institute of Japan and Kinki Branch Steel Structure Subcommittee It is described that the paint on the edge of the second floor floor beam is peeled off and traces of plasticization are observed.

  On the other hand, in Japanese Patent Laid-Open No. 11-125568 (Patent Document 1), the accumulated displacement amount of a hysteresis damper incorporated in a building frame is measured, and the deterioration state of the damping function of the hysteresis damper is evaluated and replaced. It is described that the judgment of time etc. is performed.

  The present applicant provides an elasto-plastic energy absorber for a framing body that can easily set the place where the framing body yields and can easily recover after breakage according to Japanese Patent No. 3256025 (Patent Document 2). Furthermore, according to Japanese Patent No. 3256026 (Patent Document 3), an elastic-plastic energy absorbing structure having an elastic-plastic energy absorbing panel provided with a plastic body that yields and plastically deforms by an external force exceeding a predetermined value is provided. Provides an elastic-plastic energy absorber that can be easily and inexpensively restored in a short time when it is damaged by an earthquake or the like according to Japanese Patent No. 3294495 (Patent Document 4).

September 1, 2001 Published by Japan Architecture Disaster Prevention Association, supervised by Ministry of Land, Infrastructure, Transport and Tourism, Housing Bureau Building Guidance Division, “Decision criteria for earthquake damage classification and restoration technology guidelines” p.157-p.158 May 8, 1995 Published by the Architectural Institute of Japan, Kinki Branch Steel Structure Subcommittee (editor / author) “1995 Hyogoken Nanbu Earthquake Steel Building Damage Survey Report” p.55 JP 11-125568 A Japanese Patent No. 3256025 Japanese Patent No. 3256026 Japanese Patent No. 3294495

  However, in the above-described conventional example, the technique of Non-Patent Document 1 cannot easily identify the rust-prevention paint peeling site of the building after the earthquake occurs, and the identified location may have various structural forms. Since the correlation between the peeling state of the anticorrosive paint and the degree of distortion differs depending on the individual structural form, it is difficult to evaluate. Non-Patent Document 2 only describes that the paint on the end of the second-floor floor beam is peeled off and traces of plasticization are observed, and mentions the evaluation of the deterioration of the end of the second-floor beam. It has not been.

  Further, in the technique of Patent Document 1, in the [0019] column on page 3 of the specification of Patent Document 1, “the cumulative displacement measured by the cumulative displacement measuring mechanism is mostly based on plastic displacement. However, since the elastic displacement is also measured, the accumulated displacement amount includes the elastic displacement amount.As described, the elastic displacement amount is accumulated in addition to the plastic displacement amount. There is a problem that the evaluation error of the deterioration state of the device becomes large, and early replacement is unavoidable. Further, it is necessary to separately provide a moving body such as a rotating body that moves a distance corresponding only to the amount of displacement in one direction at the time of relative displacement, and a cumulative displacement amount display member that cumulatively displays the moving distance of the moving body. There is a problem that it takes.

  Moreover, in the techniques of Patent Documents 2 to 4, the yielding point of the building after the occurrence of an earthquake is obtained by installing a load bearing element provided with an elastic-plastic energy absorber that yields by an external force exceeding a predetermined value and plastically deforms. Although it can be set easily and recovery after breakage can be easily performed, there has been a problem that it is impossible to predict the replacement time of the load-bearing element before rupture.

  The present invention solves the above-mentioned problems, and the object of the present invention is to provide a load-bearing element that can easily perform deterioration diagnosis without providing a separate member, or an earthquake-resistant element, and a deterioration diagnosis method for the load-bearing element. To do.

  In order to achieve the above object, the load-bearing element according to the present invention is a load-bearing element that is attached to a structure, and the load-bearing element has an energy absorbing portion of an elastic-plastic body, and cumulative damage of the energy absorbing portion due to external force A paint having a predetermined correlation between the value and the amount of peeling of the paint applied to the surface of the energy absorbing portion is applied to the surface of the energy absorbing portion.

  Further, the seismic element according to the present invention is an seismic element attached to a steel building, and the seismic element has an elastic-plastic energy absorbing part that absorbs seismic energy, and cumulative damage of the energy absorbing part due to an earthquake. A paint having a predetermined correlation between the value and the amount of peeling of the paint applied to the surface of the energy absorbing portion is applied to the surface of the energy absorbing portion.

  Further, a deterioration diagnosis method for a load bearing element according to the present invention is a deterioration diagnosis method for a load bearing element having an energy absorbing portion of an elasto-plastic body, the cumulative damage value of the energy absorbing portion due to external force, and the energy absorbing portion of the energy absorbing portion. A correlation between the amount of the paint applied to the surface and the amount of the paint applied to the surface is separately obtained, and the deterioration of the energy absorber is diagnosed from the amount of the paint applied to the surface of the energy absorber after the external force is generated. Features.

  According to the load-bearing element according to the present invention, it is possible to easily diagnose deterioration of the load-bearing element by estimating the cumulative damage value of the energy-absorbing part from the amount of peeling of the paint applied on the surface of the energy-absorbing part of the load-bearing element. Moreover, by setting the portion yielding due to external force to a predetermined location in the proof stress element, that is, the energy absorbing portion, it is possible to easily identify the degradation diagnosis location and to easily perform recovery after breakage. . Further, deterioration diagnosis can be easily performed without providing a separate member, so that cost can be reduced.

  According to the seismic element according to the present invention, it is possible to easily diagnose the deterioration of the seismic element by estimating the cumulative damage value of the energy absorbing part from the amount of the paint applied to the surface of the energy absorbing part of the seismic element. Moreover, by setting the place where the earthquake yields to the place where the seismic element is provided, the deterioration diagnosis can be easily specified, and the recovery after the damage can be easily performed. Further, deterioration diagnosis can be easily performed without providing a separate member, so that cost can be reduced. Therefore, it is possible to avoid over-maintenance of a long-life house having a lifespan of 50 years or more, which is economically advantageous.

  Usually, since the seismic element is housed inside the wall, there is a demand to complete the diagnosis without removing all the walls at the time of diagnosis after the occurrence of the earthquake. Therefore, by determining the mounting position of the energy absorbing portion of the seismic element in advance, diagnosis can be performed simply by peeling off a part of the wall of the part corresponding to the position of the energy absorbing portion, thereby improving the diagnostic efficiency. Furthermore, replacement is easy and recovery can be done quickly.

  According to the method for diagnosing deterioration of a load-bearing element according to the present invention, the accumulated damage value of the energy absorbing portion is estimated from the amount of paint peeled off from the surface of the energy absorbing portion of the load-bearing element after an external force is generated. Diagnosis of deterioration is easy.

  An embodiment of a load bearing element or an earthquake resistant element according to the present invention and a deterioration diagnosis method for the load bearing element according to the present invention will be specifically described with reference to the drawings. FIG. 1 is a diagram showing the structure of a seismic element provided in a steel frame building composed of columns and beams as an example of a load bearing element according to the present invention, wherein (a) shows a stationary state, and (b) shows a deformation. FIG. 2 is a diagram showing the process of displacement and load change until a predetermined amplitude is given and the energy absorbing portion of the seismic element breaks, and FIGS. 3 to 5 are elastoplastic bodies of the seismic element It is a figure which shows the peeling state of the coating material coated on the surface of this energy absorption part.

  The energy absorption part 6 of the elastic-plastic body shown in FIGS. 1 and 3 to 5 is coated with a paint. When the energy absorbing portion 6 receives a force and plastic deformation starts, the energy absorbing portion 6 starts to be damaged. As damage accumulates, the paint will also peel off. It has been confirmed by experiments conducted by the present inventors that there is a predetermined correlation between the cumulative damage value of the energy absorbing portion 6 and the amount of peeling of the paint.

  In FIGS. 1A and 1B, A is an earthquake-resistant element attached to a steel building such as a house as an example of a load-bearing element attached to a structure. Reference numeral 1 denotes an up-and-down beam, and 2 denotes left and right pillars erected between the upper and lower beams 1. Reference numeral 3 denotes a main frame body attached to the left and right columns 2 between the upper and lower beams 1, and reference numeral 4 denotes a connecting frame member installed horizontally at the center between the main frame bodies 3.

  The seismic element A shown in FIGS. 1, 3 and 4 comprises a main frame 3, a connecting frame 5, an energy absorbing portion 6, a connecting member 7 and an oblique frame 8. The connecting frame 4 is a main frame. The left and right connecting frame bodies 5 connected to 3 and the energy absorbing portion 6 made of an elastic-plastic body arranged in the center are connected by a connecting member 7, and the connecting member 7 has the left and right main frames connected thereto. A plurality of oblique frames 8 that are obliquely installed with one end connected to the body 3 are connected.

  In the present embodiment, for example, the upper and lower beams 1 and the main frame 3 are H-shaped steel (for example, SS400), the left and right columns 2 are rectangular steel pipes, the connecting frame 5 is a rectangular steel pipe (for example, STKR400), and the energy absorber 6 is A square steel pipe (for example, STKR400), the connecting member 7 is made of a steel plate (for example, SS400), the slanted frame body 8 is made of a round steel pipe (for example, STK400), and the like, and they are assembled together by welding.

  In the embodiment shown in FIGS. 3 and 4, for example, the energy absorbing portion 6 is formed of a square steel pipe (for example, STKR400), and a welded portion with a thickness of 2.3 mm, a height of 50 mm, a width of 30 mm, and both connecting members 7. The shortest distance is 52.2 mm and the radius of curvature of the welded part is 23.8 mm.

  In such a configuration, when the steel building is subjected to a large seismic force, the energy absorbing portion 6 first reaches the yield point and undergoes plastic deformation, and the rest is hardly damaged. When exchanging, the seismic element A having the energy absorbing part 6 that has been plastically deformed is removed from the left and right columns 2 and the steel frame is simply assembled by simply fixing the seismic element A with the new energy absorbing part 6 attached to the left and right columns 2. It is possible to easily return to the state.

  The energy absorbing portion 6 and the connecting member 7 made of a low yield point steel plate (high ductility hot-rolled mild steel plate) shown in FIG. 5 are fixed by a torcia type high strength bolt 9 (for example, M16 (S10T)).

  In the embodiment shown in FIG. 5, for example, the energy absorbing portion 6 is formed by pressing a high ductility hot-rolled mild steel plate into a shape shown in FIG. 5 with a U-shaped cross section, and has a plate thickness of 4.2 mm and a total length of 200 mm. The width of both ends is 110 mm, the width of the constriction is 33.4 mm, and the height of the standing piece is 14 mm. In addition, a constraining member 10 is fixed to both ends of the constriction by a torcia type high-strength bolt 9 or the like, and is configured such that plastic deformation occurs in the central portion of the constriction of the energy absorbing portion 6.

  The low yield point steel material used as the material of the energy absorbing portion 6 is generally composed of an alloy of elements such as iron and carbon and other trace amounts of manganese, nickel, phosphorus, sulfur, and the like, including carbon and other elements than iron. Low yield point steel can be made by reducing the content of copper, bringing it closer to pure iron, increasing the size of crystal grains, and adding a small amount of special elements such as niobium (Nb).

  The mechanical properties of low yield point steel materials compared to general steel materials are such that the yield point is lowered by about half, the elongation capacity is increased, and the tensile strength is lowered. And since it has the same high rigidity as a general steel material, it yields from a small deformation stage for the same force because the yield point is low. Can be absorbed. Therefore, the low yield point steel material has a larger amount of energy absorption at the time of small deformation than a general steel material.

  On the other hand, increasing the amount of steel used to achieve the same strength as a structure using ordinary steel, and making a structure using steel with a low yield point increases the plastic strain energy up to fracture by the amount of high elongation capacity. Therefore, the earthquake resistance at the time of a large earthquake is improved.

  Accordingly, the connecting frame material 4 is configured by connecting the left and right connecting frame bodies 5 and the central energy absorbing portion 6 so that a general steel material having greatly different mechanical properties and a low yield point steel material are used in combination. This makes it possible to control the mechanical behavior of the structure as intended by the designer.

  As described above, when the energy absorbing portion 6 disposed in the central portion of the connecting frame member 4 receives an external force exceeding a predetermined value acting on the steel frame due to an earthquake or the like, it yields before other parts, It consists of a plastic body designed to be plastically deformed. The yield strength is designed so that the amount of energy absorption becomes clear by appropriately changing the material, length, shape and the like of the energy absorbing portion 6.

  In addition, when the energy absorbing portion 6 is replaced with a new one, the high-strength bolt 9 is removed and plastic deformation is caused by an external force such as an earthquake, or the broken energy absorbing portion 6 is removed from the connecting member 7 to absorb new energy. The seismic element A and the steel frame can be easily returned to the original state simply by fixing the portion 6 to the connecting member 7 with the high strength bolt 9.

  The seismic element A shown in FIGS. 1, 3 and 4 comprises a main frame 3, a connecting frame 5, an energy absorbing portion 6, a connecting member 7, and an oblique frame 8. The seismic element A shown in FIG. The restraint member 10 is integrally assembled, and thereafter, an epoxy resin cation type electrodeposition paint is used for electrodeposition baking coating with a coating thickness of about 20 μm or more as a single layer. In the present embodiment, for example, ELECRON KG400 manufactured by Kansai Paint Co., Ltd. is used as the epoxy resin-based cationic electrodeposition paint.

  The coating thickness is measured with an electromagnetic film thickness meter (JIS K5400). The hardness of the coating film is equal to or higher than the pencil concentration H when the hardness of the coating film is tested with a pencil scratch tester (JIS K5400). The adhesion is 100/100 (1 mm of cutter) when the state of adhesion of the coating film that occurs when the cuts reaching the ground surface through the coating film of the test piece are made in a grid pattern is visually confirmed (the cutter is 1 mm). JIS K5400).

  Corrosion resistance is 3 mm or less on the side of the rust width when the test piece is held in a salt spray test apparatus for 500 hours and the presence or absence of rust and swelling / peeling of the coating film is confirmed (JIS K5400). The impact resistance was checked with a DuPont hardness tester for the presence or absence of cracking / peeling of the coating film when a 500 g weight dropped from a height of 50 cm and collided with the surface of the coating film (JIS K5400).

  The seismic element A electrodeposited with an epoxy resin-based cationic electrodeposition paint can follow the elastic deformation within the range of normal elastic deformation before plastic deformation and does not peel off.

  The inventors of the present invention have applied the energy absorbing portion 6 due to an external force such as an earthquake in the seismic element A in which the surface of the energy absorbing portion 6 of an elastic-plastic material that absorbs the seismic energy or the like is coated with such an epoxy resin-based cationic electrodeposition coating. The present invention has been completed by verifying by experiment that a predetermined correlation is established between the cumulative damage value and the amount of peeling of the paint applied to the surface of the energy absorbing portion 6.

  Here, in determining the cumulative damage value of the energy absorbing unit 6, first, a limit amplitude at which the energy absorbing unit 6 is deformed at one time is obtained, and the energy absorption takes several times with a predetermined amplitude in a range smaller than the limit amplitude. It is determined whether the part 6 is deformed.

  For example, FIG. 2 shows a process of displacement and load change until the energy absorbing portion 6 is broken by applying a predetermined amplitude δ. 2A is δ = Amm, FIG. 2B is δ = Bmm, FIG. 2C is δ = Cmm, FIG. 2D is δ = Dmm, and FIG. 2E is δ = Emm. Yes, A <B <C <D <E.

  FIG. 2 (f) shows the energy absorption with a constant amplitude of δ = Dmm after the amplitude δ is increased every cycle in the order of 13.1 mm → 26.2 mm → 37.4 mm → A mm → Cmm → Dmm. The process of the change of a displacement and a load until the part 6 fractures is shown.

  According to the “Performance and Design of Steel Structures (Author Hitoshi Kuwamura)” published by Kyoritsu Shuppan, the fatigue life is estimated based on the minor rule, and the cumulative damage defined by the formula: D = Σ (n / N) The evaluation is based on the value, and it is described that the fracture occurs when D = 1. In order to obtain the cumulative damage value, several samples of the energy absorption unit 6 for obtaining the cumulative damage value are prepared, and the constant amplitude loading with different amplitudes is performed in advance for examination.

  In order to obtain the cumulative damage value of the energy absorption unit 6, several samples of the energy absorption unit 6 for obtaining the cumulative damage value are prepared, and as shown in FIGS. 2 (a) to 2 (e), a constant amplitude loading test is performed in advance. Then, the relationship between the plastic strain amplitude δ and the number of repetitions N until fracture is examined. As an example, the results of the constant amplitude loading test performed in advance are as shown in Table 1 below, and the cumulative damage value will be described based on this.

  From the test results shown in Table 1 above, the damage value of the energy absorber 6 received per cycle is calculated. That is, the damage value is represented by the reciprocal of the number of repetitions N until the energy absorbing portion 6 breaks. For example, in the test body 5 of Table 1, the cumulative damage value of the energy absorbing portion 6 of the seismic element A applied with 10 cycles of amplitude δ = 15 mm is 0.02 (damage value per cycle) × 10 (cycle). = 0.20 (cumulative damage value).

  Further, as shown in FIG. 2 (f) and Table 2 below, when obtaining the cumulative damage value of the energy absorbing portion 6 subjected to the force applied by the random wave, the random wave is set to the plastic strain amplitude δ. Decompose.

  Then, the product of the damage value (1 / N) per cycle for each amplitude δ and the number of waves n for each amplitude δ included in the random wave is obtained to determine the damage value for each amplitude δ of the random wave. Ask for. The cumulative damage value can be obtained by summing the damage values for each amplitude δ of the random wave (0.5 + 0.4 + 0.2 + 0.1 + 0.0 = 1.2).

  In addition, the numerical value of damage value per cycle (1 / N) shown in the above Tables 1 and 2 is a value obtained by rounding off 3 digits after the decimal point to 2 digits after the decimal point, and the damage value for each amplitude δ of the random wave. The numerical value is a value obtained by rounding off two decimal places and one decimal place.

However, since the constant amplitude loading test is performed only at a preset amplitude, a random wave such as an earthquake is decomposed into a constant amplitude of plastic strain amplitude δ = 70, 45, 30, 20, 15 as in this example. Since it is impossible, the relationship between the number of repetitions until breakage N-plastic strain amplitude δ is expressed by an approximate curve from the results of the constant amplitude shown in Table 1 above, as shown in Table 3 below. It can be mathematically processed using δ = C × N ^−k (C and k are constants obtained by experiments).

When the cumulative damage value is actually calculated, a random wave is decomposed using a computer, and each wave of the wave is calculated from the above approximate expression: δ = C × N ^−k (C and k are constants obtained by experiments). N corresponding to the amplitude δ is obtained, and all of them are applied to the equation D = Σ (n / N) to obtain the cumulative damage value.

  3 to 5 show the peeled state of the epoxy resin-based cationic electrodeposition paint electrodeposited on the surface of the energy absorbing portion 6 of the elastic-plastic body of the earthquake-resistant element A as described above. Each energy absorbing portion 6 shown in FIGS. 3 (a), 4 (a), and 5 (a) is within a normal elastic deformation range, and peeling of the coating cannot be visually observed. The cumulative damage value of the energy absorbing portion 6 is 0.

  As shown in FIG. 2 (e), the displacement of the floor height L (2620mm) at a constant amplitude of δ = Emm is 1/200 (13.1 mm), and the amplitude δ shown in FIG. 2 (f) is increased. Even in the 0.5 cycle state, as shown in FIGS. 3 (a) and 4 (a), peeling of the coating of the energy absorbing portion 6 was not visible, and the cumulative damage value of the energy absorbing portion 6 was 0.00. .

  FIG. 2 (e) shows a state where the floor height L (2620mm) is 1/100 of the displacement (26.2mm) at a constant amplitude of δ = Emm, and the amplitude δ shown in FIG. 2 (f) is increased by 1.5. In the cycle state, the cumulative damage value of the energy absorbing portion 6 is 0.00. As shown in FIG. 4B, the width of the paint peeling portion 12 from the edge of the welded portion 11 to the welded portion 11 is about 4 mm. The paint was peeled off.

  The cumulative damage value of the energy absorbing portion 6 is 0.01 in the state of 0.5 cycle at a constant amplitude of δ = Amm shown in FIG. 2A, and from the edge of the welded portion 11 as shown in FIG. Along the welded part 11, peeling of the paint with a width of the paint peeling part 12 of about 8 mm was visually observed.

  In the state of 1/60 displacement (43.7 mm) of the floor height L (2620 mm) at a constant amplitude of δ = Emm shown in FIG. 2 (e), the cumulative damage value of the energy absorbing portion 6 is 0.01. In the 2.5 cycle state in which the amplitude δ shown in (f) is increased, the cumulative damage value of the energy absorbing portion 6 is 0.02, and as shown in FIG. The paint peeling where the width of the paint peeling part 12 was about 8 mm along 11 was visually observed.

  In the state of 0.5 cycle with a constant amplitude of δ = Bmm shown in FIG. 2 (b), the cumulative damage value of the energy absorbing portion 6 is 0.02, as shown in FIG. 3 (d), from the edge of the welded part 11. Along the welded part 11, peeling of the paint having a width of the paint peeling part 12 of about 12 mm was visually observed.

  In the state of displacement (52.4 mm) of 1/50 of the floor height L (2620 mm) at a constant amplitude of δ = Emm shown in FIG. As shown in (d), peeling of the coating having a width of the coating peeling part 12 of about 12 mm along the welding part 11 from the edge of the welding part 11 was visually observed.

  In a 1.0 cycle state with a constant amplitude of δ = Amm shown in FIG. 2A, the cumulative damage value of the energy absorbing portion 6 is 0.07, and the amplitude δ shown in FIG. In the cycle state, the cumulative damage value of the energy absorbing portion 6 is 0.08, and as shown in FIG. 3 (e), the peeling amount of the paint peeling portion 12 from the edge of the welding portion 11 along the welding portion 11 is in front. Peeling of about 40% of the entire surface of the exposed energy absorbing portion 6 was visually observed.

  The cumulative damage value of the energy absorbing portion 6 is 0.12 in a constant cycle of δ = Amm shown in FIG. 2 (a) and 1.5 cycles, and is 0. 0 with a constant amplitude of δ = Cmm shown in FIG. 2 (c). In the five-cycle state, the cumulative damage value of the energy absorbing portion 6 is 0.04, and as shown in FIG. 3 (f), the amount of peeling of the paint peeling portion 12 from the edge of the welding portion 11 along the welding portion 11 is the front. About 80% of the peeling of the coating on the entire surface of the energy absorbing portion 6 exposed to the surface was visually observed.

  The accumulated damage value of the energy absorbing portion 6 is 0.17 in the 2.0 cycle state with a constant amplitude of δ = Amm shown in FIG. 2A, and 1. with a constant amplitude of δ = Bmm shown in FIG. In the 0 cycle state, the cumulative damage value of the energy absorption unit 6 is 0.11, and in the 1.0 cycle state with a constant amplitude of δ = Cmm shown in FIG. 2C, the cumulative damage value of the energy absorption unit 6 is 0.23. 2 (d), the accumulated damage value of the energy absorbing portion 6 is 0.06 in the state of 0.5 cycle at a constant amplitude of δ = Dmm shown in FIG. 2 (d), and at the constant amplitude of δ = Emm shown in FIG. In a state where the floor height L (2620 mm) is displaced by 1/40 (65.5 mm), the cumulative damage value of the energy absorbing portion 6 is 0.03, and the amplitude δ shown in FIG. In the cycle state, the cumulative damage value of the energy absorbing portion 6 is 0.23, and as shown in FIG. Peeling the peeling amount of the member 12 is painted exposed energy absorbing portion 6 substantially entirely in front is visually.

  Further, in the energy absorbing unit 6 shown in FIG. 5, the cumulative damage value of the energy absorbing unit 6 is 0.03 in a 1.0 cycle state with a constant amplitude of δ = Bmm shown in FIG. The accumulated damage value of the energy absorbing portion 6 is 0.01 in the constant amplitude of δ = Cmm shown in c) and 0.5 cycle state, and the 0.5 cycle state in the constant amplitude of δ = Dmm shown in FIG. Then, the cumulative damage value of the energy absorber 6 is 0.01, and the cumulative damage value of the energy absorber 6 is 0.02 in a constant cycle of δ = Emm shown in FIG. In the 4.0 cycle state in which the amplitude δ shown in 2 (f) is increased, the cumulative damage value of the energy absorbing portion 6 is 0.04. As shown in FIG. Several peelings of the coating were visually observed on the exposed energy absorbing portion 6 surface.

  The accumulated damage value of the energy absorbing portion 6 is 0.06 in a 2.0 cycle state with a constant amplitude of δ = Bmm shown in FIG. 2B, and 1. with a constant amplitude of δ = Cmm shown in FIG. In the 0 cycle state, the cumulative damage value of the energy absorption unit 6 is 0.05, and in the 1.0 cycle state with a constant amplitude of δ = Dmm shown in FIG. 2D, the cumulative damage value of the energy absorption unit 6 is 0.07. Thus, in the 1.0 cycle state with a constant amplitude of δ = Emm shown in FIG. 2 (e), the cumulative damage value of the energy absorbing portion 6 is 0.10, and the amplitude δ shown in FIG. In the 5-cycle state, the cumulative damage value of the energy absorbing portion 6 is 0.10, and as shown in FIG. 5C, the amount of peeling of the constricted portion is about 30% of the entire surface of the energy absorbing portion 6 exposed to the front. The paint was peeled off.

  In the 7.0 cycle state with a constant amplitude of δ = Bmm shown in FIG. 2B, the cumulative damage value of the energy absorbing portion 6 is 0.22, and with a constant amplitude of δ = Cmm shown in FIG. In the 5-cycle state, the cumulative damage value of the energy absorption unit 6 is 0.15, and in the 1.0 cycle state with a constant amplitude of δ = Dmm shown in FIG. 2D, the cumulative damage value of the energy absorption unit 6 is 0.07. 2 (e), the constant damage of δ = Emm and the 1.5 cycle state, the cumulative damage value of the energy absorbing portion 6 is 0.17, and the amplitude δ shown in FIG. In the 5-cycle state, the cumulative damage value of the energy absorbing portion 6 is 0.28, and as shown in FIG. 5D, the amount of peeling of the constricted portion is about 60% of the entire surface of the energy absorbing portion 6 exposed to the front. The paint was peeled off.

  The accumulated damage value of the energy absorber 6 is 0.82 in a constant amplitude of δ = Bmm shown in FIG. 2B and 25.0 cycles, and 4. with a constant amplitude of δ = Cmm shown in FIG. In the 0 cycle state, the cumulative damage value of the energy absorption unit 6 is 0.25, and in the 2.5 cycle state with a constant amplitude of δ = Dmm shown in FIG. 2D, the cumulative damage value of the energy absorption unit 6 is 0.21. Therefore, in the 3.0 cycle state with a constant amplitude of δ = Emm shown in FIG. 2E, the cumulative damage value of the energy absorbing portion 6 is 0.39, and the amplitude δ shown in FIG. In the 5-cycle state, the cumulative damage value of the energy absorbing portion 6 is 0.72, and as shown in FIG. 5E, the amount of peeling of the constricted portion is about 70% of the entire surface of the energy absorbing portion 6 exposed to the front. The paint was peeled off.

  Table 4 below shows the correlation between the cumulative damage value of each energy absorbing portion 6 due to the external force such as the earthquake and the amount of peeling of the paint applied to the surface of the energy absorbing portion 6.

  In this way, a paint having a predetermined correlation between the cumulative damage value of each energy absorption unit 6 due to an external force such as an earthquake and the amount of peeling of the paint painted on the surface of the energy absorption unit 6 is applied to the energy. By coating the surface of the absorption part 6, the deterioration diagnosis of the seismic element A which is a load-bearing element having the energy absorption part 6 of an elasto-plastic material can be easily performed.

  That is, as described above with reference to FIGS. 3 to 5, the correlation between the cumulative damage value of the energy absorption unit 6 due to external force and the amount of paint peeled off on the surface of the energy absorption unit 6 is separately shown. The deterioration of the energy absorption unit 6 can be diagnosed from the amount of peeling of the paint applied to the surface of the energy absorption unit 6 after the external force is generated.

  In addition, when an earthquake-resistant element is damaged due to an earthquake or the like, interior materials such as cloth and outer walls are also damaged. It has been found that the degree of damage correlates with the amplitude of the deformation of the building. Therefore, by estimating the maximum amplitude of the building from the damaged state of the interior material and the outer wall and using only the test results corresponding to the estimated maximum amplitude, it is possible to increase the accuracy of the deterioration diagnosis of the seismic element.

  In this embodiment, the load bearing elements used in the steel frame structure are exemplified. However, the brace material of the brace structure, the column beam of the ramen structure, the joint metal of the wooden building, etc. are preliminarily determined as an energy absorbing portion that absorbs energy by plasticization. If the portion can be painted, the application of the present invention is possible.

  As an application example of the present invention, it can be used for a load bearing element attached to a structure of a building or a vehicle, an earthquake resistant element attached to a steel building, and a deterioration diagnosis thereof.

It is a figure which shows the structure of the seismic element provided in the steel frame building which consists of a pillar and a beam as an example of the strength element which concerns on this invention, Comprising: (a) is a figure which shows a stationary state, (b) is a mode that it deform | transformed. FIG. It is a figure which shows the process of the change of a displacement and load until a predetermined amplitude is provided and the energy absorption part of a seismic element breaks. It is a figure which shows the peeling state of the coating material coated on the surface of the energy absorption part of the elastic-plastic body of an earthquake-resistant element. It is a figure which shows the peeling state of the coating material coated on the surface of the energy absorption part of the elastic-plastic body of an earthquake-resistant element. It is a figure which shows the peeling state of the coating material coated on the surface of the energy absorption part of the elastic-plastic body of an earthquake-resistant element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vertical beam 2 ... Left-right column 3 ... Main frame 4 ... Connection frame material 5 ... Connection frame body 6 ... Energy absorption part 7 ... Connection member 8 ... Diagonal frame body 9 ... High strength bolt
10 ... restraint member
11 ... welded part A ... seismic element (strength element)

Claims (3)

A load bearing element attached to the structure,
The load bearing element has an energy absorption part of an elastic-plastic body,
A paint having a predetermined correlation between a cumulative damage value of the energy absorbing part due to an external force and a peeling amount of the paint applied to the surface of the energy absorbing part,
A strength element coated on the surface of the energy absorbing portion. A seismic element attached to a steel building,
The seismic element has an elastic-plastic energy absorbing part that absorbs seismic energy;
A paint having a predetermined correlation between the cumulative damage value of the energy absorption part due to the earthquake and the amount of peeling of the paint applied to the surface of the energy absorption part,
A seismic element characterized in that the surface of the energy absorbing portion is painted. A method for diagnosing deterioration of a load bearing element having an energy absorption part of an elastoplastic material,
The correlation between the cumulative damage value of the energy absorbing part due to external force and the amount of peeling of the paint applied to the surface of the energy absorbing part is obtained separately,
A method for diagnosing deterioration of a proof stress element, wherein deterioration of the energy absorbing portion is diagnosed from a peeling amount of a paint applied to the surface of the energy absorbing portion after an external force is generated.

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